Not Applicable
Spectrometers are known and used to provide a spectral image of a scene. FIG. 8 illustrates an example of a known spectrometer 800. In this spectrometer 800, light from an image 810 passes through a slit 820 and a first concave mirror 830 of a reflective assembly 835 receives an image 812. The first mirror 830 is in a light path from the slit 820 and reflects light to a convex diffraction grating 860. The convex diffraction grating 860 receives the reflected light from the first mirror 830. The diffraction grating 860 spectrally disperses the image received from the first mirror 830 into a spectral image 814. A second concave mirror 840 of the reflective assembly 835 receives the spectral image 814 from the diffraction grating 860 and reflects the spectral image 814 to a detector 850, such as a CCD array of a camera or other device.
Preferably, the diffraction grating 860 is a known aberration corrected convex diffraction grating, which provides for simultaneous high spatial and spectral imaging resolution and low distortion. By using the aberration corrected convex diffraction grating, the spectrometer 800 provides a high resolution that may function for a wide variety of applications such as optical communication channel switching.
An optical communication channel switch includes an aberration corrected spectrometer adapted for receiving plural channels of communication in a one dimensional array of sites where each site corresponds to a source, and a channel selector for selectively switching channels. After receiving the plural channels, the aberration corrected spectrometer provides the channels in a two dimensional array in which channels are distributed in rows (or columns) of similar frequency and different sources and in columns (or rows) of differing frequency and common sources. The channel selector selectively switches channels among sites in the two dimensional array and provides a single dimensional reconfigured array of frequency separated channels that is combined into the two dimensional array. Another aberration corrected spectrometer receives the selectively switched two dimensional array and combines the channels into a single dimensional array of sites having one or more frequency separated channels.